Insulator



June 15, 1948. J TAYLOR 2,443,435

INSULATOR Filed June 23, 1945 I 2 Sheets-Sheet 1 I n venlor JOHN J.THYLoR Attorney J. J. TAYLOR June 15, 1948.

INSULATOR 2 Sheets-Sheet 2 Filed June 25, 1945 fza 6.

ventor YLOE By Z44 FM Ailorney Patented June 15, 1948 UNI TED SINSULATOR "John 'J. "Taylor, Wadsworth, Ohio, :-:assig-nor nto The Ohio?Brass Z'Eompany, f-Mansfieid, i Dhiopa corporation mffiNew; JerseyAppIication'JunefZS, 1945, Serial'No; 6013248 21 Claims. 1

'Thisinvention relates to'line insulators and particularly insulators ofthe suspension type although useful in connectionwith other "typesofinsulators. The invention has for ,itsbbiect theprovision of meanstopreVentthe cracking of the vitreous portion of the insulator due tothe oxidation of metallic elements forming parts of the insulator.

"The invention is exemplified inthe combinationand arrangement of thepartsfsho-wn in the accompanying drawings andc'describe'd in" thefollowing specification, and it is more particularly pointed out in theappended claims.

In the drawings .Fig. lisa side View of one'iormiofimyinvention, ,inpartial section.

"Fig. 2 is. an enlarged side View in ;:partial tion of they pin showninFigJl.

vvFig.3 isa side view of the shelrinliigfz.

'Fig. 4 is a section on'the line44'ofFig.i2.

.Fig. 5 is. a, section'on the line 55,ofFig.' 2.

-'Fig. 6 is aside viewofwanother form'o'f Invinvention, in partialsection.

Fig. "'7 is a full side view. of the pin'shownin Fig. 6.

'Fig. 8 is an enlarged section on the'line. 8-"8 of Fig. 7.

Fig.9is an enlarged section ontherline9-9 .ofFig. '7.

Line insulators, not infrequently, are composed of one or more porcelainorothervitreouselementsiassociatediwith one or moremetallicielements,particularly in' the case of suspensiontype insulators.

The metal partsare usually 10f "'iron' whichis galvanized to protect, itfrom corrosion an'd in some cases attempts are made to protect thegalvanizing coating by a thin coating "thereon of waX, varnish or .asimilar material.

In the suspension type of insulator.in"which a vitreous disc/such asshown in"Fig.1'is provided with a metal cap and pin, in which the metalparts are secured to the disc by interposed icevment, the pressureexerted by the corro'ding pin ,.made of stainless steel,copper'baseralloys'and steel with a variety of protective coatings, but

vit has been'found all of these. are 'liableto' attack by the combineddestructive ability of moisture,

leakage current, temperature and'theactive oxidizing conditions broughtabout by electrical overstress in aconfined area.

Metal par-ts of conventional types of insulators when made of bronzewill corrode, but s-uchcor- .rosion produces a soft and relativelythincoat- .ing -as compared with that of .apinof ferrous metal and thedang-er of damaged'zdisesais' therefore much less. llowever underipresent -:conditions one is limited as to availablermetalsi and fromthestandpoint of cost :the. use .ofz bronze; is

5 justified only in exceptional cases.

An I insulator l of the type reierred .130; above is shown in the UfSPatenti 94?;274 zof. January.;25,

1910. The pinin this type ofuconstruction irridue course of time beginsto oxidize or rust iati'the 10 lower edge :of the oement: and:thisi'rust: eats its -way-upward-.along the-pin and in the cease .of :aniron pin,either plai=n .on galvanized, the coating ofrust-swells or'grows, thus increasing mater-ially the diameter of the-cpin-iandintimethe pressure exerted on the disc=;through. theinterposedccement-oauses the.vitreousridiscttorrupture and the cement tochip-away.

It is the purpose of my invention,.:notwsoimuch 'to preventcorrosion 10fthe pinibvthea exclusion *of moisture, :butato provide 'meansfiWhGlEbYillE accumulation or growth :of the :c'oating of rust willnot'brin excessive pressure uponxthezcement arldwitreous disc.

In-Fig. li;is :shown ans insulator impartial secti on in :which'isincorporated means ior.;preventing pressure upon the cement and discandzstill =-retain zthe benefit -of..a:conduotorextending as iar as thelower edge of the ropeningin thecdisc.

ln 1, thedisc-l iis formedtiromn .vitreous insulating materialzsuchasporcelain on glass and has1the; head.2 .zenclosedzin agmetalscapi 3which =is=secured to theiiheadcbyxtheiinterposedcement 4, and ines the ssocket 5 :to :receive; supporting means.

The head 2 is provided withzzthetholezoraoav ity 6 inWhiChJiSrpOSitiOnfid the LiniPzem-bdddefd in cement 'l.':-To:secureaa;propen hold.oi,.the.;cement --to'-"-theout'erandirmerosnriacesoof :the? head; the same is usuallyupreparedvwithaxsandedssuriace aan-d the cement iusualiy'. used is .quite near:Bortilandvcement' which; is; inclinedato develop radial:weaknesseszdue:tocdryingsshrinkage.

The: pin :P :comprisesraccentralsslrank .38 ir=om which project :\aaaplurality cot integral-1y iiormed rannular 'ffianges -19 whereby ;aifirm interlock is .seoured .withwthe cement 51. .At the lowerr-endviofqtlie zshank :8 tis-z-a'knob l0 which-will interfit :with-thessocket 1 5:.on a; like insulator -.positioned wbelDW.

zTheflanges-B- may. beesuch tl'iat they willprac- -tieally resist. allwielding of 4 the ,pin under .an axial ,IoadorHtheY may Joe suficientlythin to ..perm.i-ta slightyieldingoilthe pin relative to the cementunder sufficientlloading.

-'I.o prevent such destructive corrosion as will develop along thepin.shankiabove'theinner-edge of the conventionaltype --of insulator"shown I in the above patent,the pin includes a 'shel1,=*sleeve'orcollar'l lwhich'is secured to one of the-flanges 9, preferably the"lower flange.

One purpose of this shell or sleeve is to provide an open space l2around the pin shank which is usually in contact with the cement.

Another purpose of the sleeve H is to retain the interposed cement aswould be the case if it filled the entire space between the pin shankand disc. To prevent undue pressure upon the disc and the cement betweenthe shell and disc, certain features are incorporated in the sleeve.

The sleeve I is formed preferably from a tube of proper length andmaterial and by means of dies formed into the shape shown in Fig. 3 andthis formed sleeve is then positioned on a flange 9 and then the entireassembly is hot dip galvanized, This places a protective coat overtheentire surface of the pin including the shell and not only integrallysecures the sleeve to the flange but forms a sealed joint therebetweenas though welded.

Since the stress set up by the products of corrosion is radial, I findthat in order to give proper radial flexibility to the sleeve II, itshould be corrugated vertically or in an axial direction as shown inFigs. 3 and 4. Such corrugations have been found to contribute in a verydecided degree, to the radial flexibility of sleeve ll and provide asleeve of an entirely different order of radial rigidity from that of aplain cylindrical or uncorrugated sleeve or from a sleeve having annularor ring corrugations, even though the latter types are made of materialof impractically thin section.

An insulator of the type shown in Figs. 1 and 6 may be subjected tovertical loads of from 15,000 to 25,000 pounds or more. This invariablycalls for some relative vertical yielding of the parts, which however isvery slight. The tendency is for the pin to yield to a greater degreerelative to the disc than the cap yields relative to the disc.

Any annular or ring corrugations on the sleeve i! will interlock withthe cement and if the sleeve is interlocked with the pin also there willbe danger of the cement and discs I and, 2| being checked and broken intime. Also the annular or ring corrugations tend to stiffen the sleevein a radial direction thus destroying its radial flexibility and abilityto yield under the products of corrosion.

Further, vertical or axial corrugations, while they interlock with thecement, do not resist the pin yielding under load or for other reasonsand therefore do not stress the cement and disc and since they tend toincrease the radial flexibility of the sleeve, the danger of injury tothe cement and disc is very remote. The sleeves H and 3| do not take anyof the vertical load upon the pin.

In the construction of the sleeve shown in Figs. 3 and l, the verticalcorrugations do not extend throughout the length of the sleeve H butblend into a cylindrical section at the line of juncture between theflange 9 and sleeve Better performance would be expected of aconstruction in which the corrugations extended the full length of thesleeve, but in such a construction and to permit hot-dip galvanizing ofthe entire assembly, the mating surface on the pin would requirecorresponding fluting,

If the sleeve is made of cold drawn seamless tubing, corrosion will, inthe course of time, set in starting at the lower edge of the sleeve andgradually creeping upward along the sleeve next to the cement. Thiswill-naturally cause a pressure to be exerted upon the porcelain'throughthe interposed cement as a result of the resistance of the sleeve Thisresistance may be considerable as corrosion builds up unless the sleeveis properly designed with respect to the ultimate resistance of the discto splitting.

It has been found in a certain insulator construction of the type ofFig. 1 that a pin according to Fig. -2 using a sleeve according to Figs.3 and 4 made of cold drawn seamless steel tubing of 0.032 metal andcorrugated to control its radial resistance and with an assumed 0.01"coating of corrosion products will develop pressures in the order of.1000 pounds per square inch and other tests have shown that a radialpressure of about 5000 pounds per square inch necessary to split thedisc of the construction shown.

A steel sleeve is preferably used as it is easily formed, is elastic andreadily galvanized and under war restrictions it is less difficult toprocure than non-ferrous materials.

In Fig. 6 is shown a somewhat different construction of insulator but inwhich the same principle is involved asin Fig. 1 but the type of pinshown in Fig. 7 may be adopted for use in the disc shown in Fig. l.

In Fig. 6, there is a vitreous disc 2| provided with a head 22 and cap23 secured to the head by interposed cement 24, the surface ofthe headbeing sanded. The cap also has a pin P positioned in the socket 26. Thepin is embedded in cement 27 which is secured to the disc by a sandedsurface, The cement used is usually 2. Portland cement which has theweakness previously stated.

The pin P comprises a central shank 28 from which project severalannular flanges 29 whereby a secure interlock is formed with the cement21. The pin has at its lower end a knob 30 which will interfit with thesocket 25 on an insulator positioned below.

To prevent the destructive corrosion along the pin shank opposite thelower portion of the cement 2'! from injuring the cement and disc, thepin shank is provided with a shell or sleeve 3| which is secured to aflange 32.

This sleeve 3| is inverted but forms a space 33 around the pin shankwhich may be entirely enclosed or ventilated as by a small opening 34through either the sleeve 3| or flange 32.

The sleeve 3| is vertically corrugated as is the sleeve H and for thesame purpose and reasons and the free corrugated portion extends wellinto the cement .21. The lower portion of the sleeve 3| is placed inposition on its flange 32 and the entire assembly is then hot-dipgalvanized.

Under some circumstances the air trapped in the closed space 33 as thepin in its inverted position is inserted into the soft cement at thetime of assembly, may prevent cement entering the space 33, but if it isdesired to keep the space 33 absolutely clear of cement the space may befilled or protected from filling with a resilient compound or materialwhich will not affect the yielding properties of the sleeve 3|.

The sleeve 3| will perform similar to the sleeve H of Fig. 1 undercorrosive action as it occupies the same relative position as sleeve H.The opening 34 will tend to ventilate the space 33 thereby preventingmoisture being drawn in between the sleeve and cement due to changes involume of entrapped air.

Under some conditions the sleeve may be a plain cylinder of uniformdiameter throughout vertical slots on perforations. to control the said.

resistance. I

The sleeves it and 31 are each securely attached to its respective pinbothmechanically and electrically since-theparts are galvanized.

after assembly.

By knowingthe minimum value at which. the

vitreous disc will'break, which will vary-in different constructions andthen. harmonizing the material, construction and relation ofv the sleeveand pinaccordingly and allowing for a sufilcient factor of safety thedanger of injury to .the disc as a result of forces exerted by theproducts of corrosion may be not only practically/eliminatedbut the lifeof the insulator materially. prolonged.

While Figs. 1 and fi show-my improved type of pinas applied toinsulators of the suspension type, it may be applied to other types" ofcommonly used insulators on the=market Where the same problems arepresent.

While I have shown and-described preferred embodiments of the invention,Ireserve the right co-make such changes in form, constructionlandarrangement of parts as will not'depart from the spirit of the inventionor-scope of the claimshereunto appended.

I claim:

1. An insulator comprising a vitreous body having a head portion, ametal supporting member secured to the exterior surface of the headportion, the headportion provided with an open end cavity, a supportingpinmounted in the cavity and secured therein by interposed cement andradially compressible means surrounding the pin for a distance back fromtheopen end of said cavity, the said means being spacedfrom thepin oversubstantially the whole of saiddistance'whereby radial pressure betweenthe said cement and the said means will cause the said means to yieldradially.

2'. In an insulator comprising a vitreousbody provided with aheadportion and a metal supporting member secured to the exteriorsurface of the head portion-, thehead portion provided with a cavityopen atone endand a supporting pin of metal mounted in the cavityandsecured to the body by interposedholding material,- the combinationwith the pin of a metal sleeve surrounding the pin for a distance backfrom open end of saidcavity and'holding material interposed between thesleeve andthe vitreous body, the sleeve provided with axially extendingcorrugations spaced circumferentially thereof whereby the radialflexibility ofthe sleeve is enhanced to prevent damage to-the interposedholding material and to the body as a result of pressure between theshell-and the cement.

3. In an insulator-comprising a vitreous body provided with aheadportion and supporting means secured to the head portion, the head portion provided with a cavity open atone end-and a metallic supportingpinmounted in-the cavity and secured therein by interposed materiaL-thecombination with the pin of a-sleeve surrounding the pin for adistance-back fromthe-open end of said cavity whereby the said materialfor said distance is held away from the pin and providing an openend-space around thepin for said distance, the-sleeve;beingprovided withmeans spaced cireurnferentially thereof te en-' 6v hance the radialflexibilityszthereofi whereby-damagetowthe vitreous body; is prevented.

4t- In-an insulator comprising a vitreous body provided withan-topensendi-cavity and-a. metallic supporting 1 pin positioned in.the: cavity: and secured therein by holding .-material, the *combinationwithisaid pini of a sleeve having. one endsecured to the pinandformingalspace with said pin and open at.:theother: end and also provided-.with: axially disposedcorrugationsv spaced circumferentially thereofland-interlocked with said'holding material whereby rotation of thesleeve relative to-the holding material is prevented but: axialmovement; of the sleeverelative to the holding material is permitted.

5: Inaninsulator adapted to support other insulators and comprising avitreous body providedwith an open end cavity-and a metallic pinpositioned in the cavity and-secured therein by holdingmaterial, thesaid pin supporting-the suspended load thereon, the combinationwiththepin of asleeve posltioned inthe cavity and surrounding the pinfor apredetermined distance away from-the said open end, the sleevemechanically and electrically secured to the pin and-forming aspaeeabout the pinfor's'aid distance and contacting with the oppositelydisposed holding material, the sleeve provided with axially disposed:means spaced circumferentlally of it to interlock with the holdingmateriali whereby the-sleeve may yield relative to: the holding materialdueto the-load on the pin without assuming any of the load.

6; In an insulator adapted to i support other insulators andcomprising avitreous body'provlded with an: open end cavity and amet'allic pinpositioned in the cavity and securedtherein by holding material, the:said pin supportingthe suspended load-thereon, thecombination with the:pin' of a sleeve positioned: in the cavity and surrounding the pin for apredetermined distance away from the said open end, the sleevemechanically.and-electrically secured tothe pin and forming aspace-aboutthe pinfor said distance andcontacting with the oppositelydisposed holdin material, the sleeve provided withirregularities lyingaxially thereofandspaced' circumferentially of it to co-ntrclthe radial.flex-ibi-lity'ofthe sleeve whereby the sleeve'will yield-radially topressure exerted upon the holding material and sleeve and therebyprevent injury to the vitreous body.

' 7-. An insulator: comprising a dielectric member'and a metallic loadsupporting member secured together by interposed material, resilientflanges spaced' along a length of the load supporting memberto-transmitthe load on it to the dielectric member through the'interposed material and to permit theload supporting member to yieldrelative to the interposed material under said lead, radially yieldablemeans surrounding the load supporting member for a portion of: thelength of the load supporting memher and securedthereto to movewith'thewload supporting member as it yieldsunder load,-the said meansprovided with axially extending corrugations-spaced circumierentially ofit to'efiect the radial yield of said'means underradialuforcesactingthereonto prevent injury to the interposedmaterialandthe'di'electric member, the said corrugations interlocked withtheinterposed material whereby-rotation oizthezradially yieldablemeansrelative to the-interposed.material is prevented withoutv preventing;the: said:v means yielding relative to the interposed material.

8. In an insulator comprising a dielectric member and a metallic loadsupporting member secured together by holding material, the combinationwith the'load supporting member of radially yielding means surroundingthe load supporting member for aportion of its length and spacedtherefrom and securely contacting the holding material and the, loadsupporting member and subject to radial forces directed toward the axisof the load supporting member, the radial yielding means being soconstructed and related to the holding material and the dielectricmember that the radial force required to cause the radially yieldingmeans to yield is less than the radial force required to damage thedielectric member.

9. An insulator, comprising a load supporting member having holdingmeans thereon, a dielectric member, holding material interposed betweenthe load supporting member and the dielectric member to secure themembers together, a sleeve of metal interposed between the holdingmaterial and the load supporting member, the said sleeve spaced from theload supporting member but engaging the holding material, the sleevebeing so constructed and related to the load supporting member and tothe dielectric member that the sleeve is radially flexible but axiallyrigid.

10. An insulator, comprising a load supporting member, a dielectricmember, holding material interposed between the load supporting memberand the dielectric member to secure the members together, the loadsupporting member comprising a rigid member and a radially compressiblesleeve of metal having one end secured to the rigid member and thebalance of the sleeve spaced from the rigid member, the said sleevebeing interposed between the rigid member and the holding material andprovided with an opening into the space between the sleeve and the rigidmember.

11. An insulator comprising a dielectric member, and a load supportingmember and means securing the members together, a radially flexiblesleeve formed with a plurality of axially extending means spacedcircumferentially of it to control the flexibility of the sleeve, oneend of the sleeve being integrally secured to the supporting member andthe other end spaced from the supporting member.

12. In an insulator pin comprising a rigid member and means thereon tointerlock with holding material to secure the pin to a dielectricmember, the combination with the member of a sleeve of relatively thinmetal having axially extending corrugations spaced circumferentially ofit to efiect radial flexibility of the sleeve, one end of the sleevebeing secured to the rigid member and the other end of the sleeve beingspaced from the rigid member.

13. In an insulator pin comprising a rigid member and having projectingflanges spaced along a portion of the length of the rigid member, thecombination with the member of a metallic sleeve of relatively thinmaterial surrounding the rigid member'for a portion of the length of therigid member, means secured to the rigid member and-to one end of thesleeve to hold the sleeve in spaced relation to the rigid member, thesaid space being closed at one end and open at the other end, and acoating of protective metal applied while molten to the aforesaid partsof the pin wherebythe parts are rendered resistant to corrosion and theparts united to form a uni tary pin.

14. An insulator pin comprising a rigid shank and means on a portion ofthe shank to interlock with holding material to secure the pin to adielectric member, a metallic sleeve surrounding-a difierent portion ofthe shank, means sup-.

porting the sleeve in spaced relation to the shank and axially extendingirregularities forming a part of the sleeve and spaced circumferentiallyof it to control the radial flexibility of the sleeve whereby the sleevewill be flexible in a radial direction and rigid in an axial direction.

15. In an insulator pin comprising a rigid shank and means on a portionof the shank to interlock with holding material to secure the pin to adielectric member, the combination with the shank of a sleeve ofrelatively thin metal surrounding a portion of the shank adjacent thefirst said portion and in spaced relation to the shank, the sleeveprovided with axially extending means spaced circumferentially of it tocontrol the radial flexibility of the sleeve in the direction of theshank, one end of the sleeve secured to means on the shank to maintainthe sleeve in position relative to the shank and to form a sealed jointtherewith while the other end of the sleeve remains free of said shank.

16. An insulator pin comprising a rigid shank provided with means on aportion thereof to interlock with holding material to secure the pin toa dielectric member, a sleeve of relatively thin metal surrounding theshank, means to secure the sleeve to the shank and hold it in spacedrelation to the shank, a plurality of corrugations forming a part of thesleeve which extend axially thereof andare spaced circumiferentially ofit to interlock with the holding material to prevent rotation of thesleeve and rigid shank relative to the holding material withoutpreventing axial movement of the sleeve and shank relative to theholding material due to axially loading the pin.

17. An insulator comprising a dielectric member and a load supportingmember and holding means securing the members together, a radiallyflexible sleeve formed with-a plurality of axially extending meansspaced circumferentially of it to control the flexibility of the sleeve,the sleeve forming a closed space about a portion of the load supportingmember and having one end secured to the load supporting member.

18. An insulator comprising a dielectric member and a load supportingmember and holding means securing the members together, a radiallyflexible sleeve provided with means spaced circumferentially of it tocontrol the flexibility of the sleeve, the sleeve forming a closed spacearound a portion of the load supporting member and having one endintegrally secured to the load supporting member at a point spaced fromthe holding means.

19. An insulator pin comprising a rigid shank and means on a portion ofthe shank at one end to interlock with holding material to secure thepin to a dielectric member, means at the other end of the shank to makean attachment thereto, a metallic sleeve surrounding a portion of theshank between the said means and forming a space between the sleeve andshank, the end of the sleeve toward the first said means being free toyield radially and the end of the sleeve toward the second said meansbeing integrally secured to the shank.

20. A radially yieldable sleeve for the load supporting pin of aninsulator which is strong enough to withstand the radial stress set upin the insulator on corrosion and comprises a shell of relatively thinmetal open at both ends, one end for a short distance being circular incrosssection and the balance of the sleeve provided with longitudinallyextending means spaced circumferentially thereof to control theflexibility of the said balance of the sleeve to external pressuresexerted thereon, the sleeve being free from longitudinal irregularitieson its outer surface which would prevent it from yielding axiallyagainst surrounding holding material under load.

21. An insulator comprising a body of vitreous insulating material witha cavity in the bottom of the insulating material, means at the top ofthe insulator by which the insulator is supported, a load-supporting pinwith one end secured in the cavity by holding material so as to carry aload, a pin emerging from the holding material within the cavity, ametal element located about the pin at approximately the level of themouth of the cavity the inner sunface of which is there spaced from theshank of the pin, its outer surface being in contact with holdingmaterial which connects it with the walls of the cavity, said elementbeing formed with irregu- REFERENCES CITED The following references areof record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,325,875 Limont Dec. 23, 1919 151,489,690 Austin Apr. 8, 1924 1,489,809 Austin Apr. 8, 1924 1,490,080Austin Apr. 15, 1924 1,645,447 Peck Oct. 11, 1927 1,653,117 Peck Dec.20, 1927 20 1,716,123 Goddard June 4, 1929 FOREIGN PATENTS NumberCountry Date 413,808 France Aug. 19, 1910 25 424,637 Great Britain Feb.22, 1985

